Merge pull request #675 from fartem/54_Spiral_Matrix

2024-07-17 v. 6.1.8: added "54. Spiral Matrix"

Author: fartem

README.md

@@ -483,3 +483,4 @@ Profile on LeetCode: [fartem](https://leetcode.com/fartem/).
 | 48. Rotate Image                                            | [Link](https://leetcode.com/problems/rotate-image/)                                            | [Link](./lib/medium/48_rotate_image.rb)                                            |
 | 49. Group Anagrams                                          | [Link](https://leetcode.com/problems/group-anagrams/)                                          | [Link](./lib/medium/49_group_anagrams.rb)                                          |
 | 53. Maximum Subarray                                        | [Link](https://leetcode.com/problems/maximum-subarray/)                                        | [Link](./lib/medium/53_maximum_subarray.rb)                                        |
+| 54. Spiral Matrix                                           | [Link](https://leetcode.com/problems/spiral-matrix/)                                           | [Link](./lib/medium/54_spiral_matrix.rb)                                           |

leetcode-ruby.gemspec

@@ -5,7 +5,7 @@ require 'English'
 ::Gem::Specification.new do |s|
   s.required_ruby_version = '>= 3.0'
   s.name = 'leetcode-ruby'
-  s.version = '6.1.7'
+  s.version = '6.1.8'
   s.license = 'MIT'
   s.files = ::Dir['lib/**/*.rb'] + %w[bin/leetcode-ruby README.md LICENSE]
   s.executable = 'leetcode-ruby'

lib/medium/54_spiral_matrix.rb

@@ -0,0 +1,32 @@
+# frozen_string_literal: true
+
+# https://leetcode.com/problems/spiral-matrix/
+# @param {Integer[][]} matrix
+# @return {Integer[]}
+def spiral_order(matrix)
+  top = 0
+  bottom = matrix.length - 1
+  left = 0
+  right = matrix[0].length - 1
+  result = []
+
+  while top <= bottom && left <= right
+    (left..right).each { |i| result << matrix[top][i] }
+    top += 1
+
+    (top..bottom).each { |i| result << matrix[i][right] }
+    right -= 1
+
+    if top <= bottom
+      (left..right).reverse_each { |i| result << matrix[bottom][i] }
+      bottom -= 1
+    end
+
+    if left <= right
+      (top..bottom).reverse_each { |i| result << matrix[i][left] }
+      left += 1
+    end
+  end
+
+  result
+end

test/medium/test_54_spiral_matrix.rb

@@ -0,0 +1,30 @@
+# frozen_string_literal: true
+
+require_relative '../test_helper'
+require_relative '../../lib/medium/54_spiral_matrix'
+require 'minitest/autorun'
+
+class SpiralMatrixTest < ::Minitest::Test
+  def test_default
+    assert_equal(
+      [1, 2, 3, 6, 9, 8, 7, 4, 5],
+      spiral_order(
+        [
+          [1, 2, 3],
+          [4, 5, 6],
+          [7, 8, 9]
+        ]
+      )
+    )
+    assert_equal(
+      [1, 2, 3, 4, 8, 12, 11, 10, 9, 5, 6, 7],
+      spiral_order(
+        [
+          [1, 2, 3, 4],
+          [5, 6, 7, 8],
+          [9, 10, 11, 12]
+        ]
+      )
+    )
+  end
+end